Multi-channel gate driver package with grounded shield metal

ABSTRACT

A multi-channel gate driver package includes a leadframe including a first, second, and third die pad. A transmitter die includes first and second transmitter signal bond pads, a first receiver die including a second signal bond pad, and a second receiver die including a third signal bond pad. A bond wire is between the first transmitter signal bond pad and the second signal bond pad, and between the second transmitter signal bond pad and third signal bond pad. A ring shield is around the respective signal bond pads. A downbond is from the second ring shield to the second die pad, and from the third ring shield to the third die pad. A connection connects the first and second transmitter ring shield to at least one ground pin of the package. The second and third die pad each include a direct integral connection to the ground pin.

FIELD

This Disclosure relates to multi-channel gate driver packages that havea mechanism for improving channel-to-channel isolation.

BACKGROUND

Multi-channel gate driver packages are for driving a plurality of powermetal oxide semiconductor field effect transistors (MOSFET) or powerinsulated gate bipolar transistor (IGBT) devices, that needchannel-to-channel isolation to properly operate as intended which iswith independent channels (no cross coupling). In one arrangement themulti-channel gate driver package includes a transceiver die, a firstreceiver die, and a second receiver die, where the transceiver iselectrically isolated (generally operated at a relatively low voltage)from the receiver die (generally operated at a relatively high voltage)using an isolation capacitor or isolation inductor as the isolatorconnected in series on or between the transceiver die and the receiverdie(s) configured to block direct-current (DC) voltages from passingthrough to the lower voltage side, while enabling signals to passthrough.

Fast switching for a high voltage or high-power gate driver package isdesirable because the receiver of the gate driver package acting as aswitch dissipates the most power during switching, switching meaningwhile in a state between being fully “off” and being fully “on”. Byminimizing the switching time and, therefore the heating of the gatedriver package, the gate driver package can be allowed to switch morepower to its application circuit, typically a power converter, such as aDC to DC converter. Fast switching is also needed to provide relativelyfast rising output pulses for a variety of different applications.

SUMMARY

This Summary is provided to introduce a brief selection of disclosedconcepts in a simplified form that are further described below in theDetailed Description including the drawings provided. This Summary isnot intended to limit the claimed subject matter's scope.

Disclosed aspects recognize during high slew rate (dV/dt) switchingoperation of a multi-channel gate driver package, because themulti-channel gate driver package has capacitive coupling between itsadjacent channels, such as between a first channel and a second channelin a dual-channel isolated gate driver, the capacitive coupling betweenthe channels can create false output signals leading to erroneous gatedriver package operation. Failures of multi-channel gate driver packageshave been observed from standard process variation, e.g., wire sweeptesting. During assembly manufacturing there is the potential for thebond wires to sweep (move) resulting in the bond wires for therespective receiver channels coming closer together as compared to theseparation distance designed for, which can increase their capacitivecoupling that can adversely impact the desired channel isolationrequirements.

Disclosed aspects recognize the transceiver of the multi-channel gatedriver package uses differential signaling to suppress common-modecoupling to the (high-voltage) HV domain. The coupling in the case of adual-channel device occurs between the 2 receiver channels (i.e.,receiver channel A and receiver channel B). Each channel is generallykept at a different potential which brings up the need for the channelisolation. Due to the manufacturing process variations, measurable noisecan be coupled from receiver channel A to receiver channel B andvice-versa Common mode coupling is not a problem for a single channelmulti-channel gate driver package.

However, for a multichannel device such as a dual-channel gate driverdevice having adjacent bond wires that go from the transmitter die torespective receiver die, the differential signaling can appear asresidual signals on an adjacent channel when the two receiver channelsswitch separately, causing erroneous multi-channel gate driver packageoperation. The recognized root cause of this cross-channel coupling isthe high sensitivity to mutual (parasitic) capacitance coupling betweenthe receiver channels resulting from the adjacent bond wires between thetransmitter die and the respective receiver die. In the case of a dualchannel device, there are 2 receiver die, a first receiver die onchannel A [RXA] and a second receiver die on channel B [RXB] and theleadframe which is between the adjacent bondwires that can cause channelcross coupling. Reducing the package mutual capacitance without changingthe position of the bondwires is how disclosed aspects address thiscross-coupling problem.

Disclosed aspects include multi-channel gate driver packages with addedgrounded shield metal that reduces this mutual capacitance betweenadjacent receiver channels resulting in a reduced level ofchannel-to-channel cross coupling. The grounded shield metal includeswhat is termed herein a ring shield that can use the same top metallayer that is used for the bond pads on the die positioned around thebond pads on each of the die that are involved in the connectionsbetween the transmitter die and the respective receiver die. The bondpads involved in these connections are referred to herein as beingsignal bond pads. The ring shield on the receiver die includes adownbond (a wirebond) to the respective die pad for each of these die,where the respective die pads are each directly shorted to a ground pinof the package. The ring shield can also be on the transmitter die whenthe transmitter die includes a peninsula shaped metal region extendingfrom the die pad of the transmitter die, where the peninsula shapedregion includes downbonds to the ring shield on the transmitter die tofurther improve shielding and thus further reduce cross channelcapacitive coupling.

Disclosed aspects include a multi-channel gate driver package comprisinga leadframe including first, second, and third die pad. A transmitterdie includes first and second transmitter signal bond pads, a firstreceiver die including a second signal bond pad, and a second receiverdie including a third signal bond pad. A bond wire is between the firsttransmitter signal bond pad and the second signal bond pad, and betweenthe second transmitter signal bond pad and third signal bond pad. A ringshield on each die is positioned around the respective signal bond pads.A downbond is from the second ring shield to the second die pad, andfrom the third ring shield to the third die pad. There is a connectionconnecting the first and second transmitter ring shields to at least oneground pin selected from the plurality of leads. The second and thirddie pad each include a direct integral connection to a ground pin.

Disclosed grounded ring shields have been found to reduce the problem ofa gate driver channel glitch and wire sweep sensitivity, both due to areduction in cross channel capacitive coupling. Disclosed aspects do notadd any circuitry to any of the die of the multichannel gate driverpackage. As used herein, a ‘ring’, such as when used in the term ringshield, means an enclosed shape that encloses a signal die pad, such asbeing circular or substantially circular, elliptical, rectangular, orsquare shaped.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale, wherein:

FIG. 1 depicts a block diagram representation of a known dual—channelgate driver package showing signal bond wires from signal bond pads onthe transceiver die to signal bond pads on the first receiver die, andother signal bond wires from other signal bond pads on the transceiverdie to signal bond pads on the second receiver die. The respectivereceiver die are each shown driving the gate of a power NMOS transistorof a power NMOS device that is the power transistor part of a powerconverter circuit. Due to cross coupling associated with the mutualcapacitance (with example values of mutual capacitance shown) betweenthe respective signal bond wires associated with the respectivechannels, some of the signal for the first channel shown as channel Aoutputted by the package pin OUTA when channel A is active, is alsopresent on the second channel driven by the second receiver die shown aschannel B on the package pin OUTB shown being a square wave as OUTA′,when channel B should instead be inactive (and thus have no signal onthis pin due to no signal coming from the transmitter die).

FIG. 2 depicts a disclosed grounded shield metal feature shown in asimplified form as a trace (the trace/guard metal feature is labeled asbeing grounded but is not shown grounded which it will be) that islocated between two adjacent metal features shown as 51 and S2 that caneach represent bond wires. The trace being grounded and positionedbetween 51 and S2 reduces the mutual capacitance between the adjacentmetal features S1 and S2.

FIG. 3A shows a known dual channel gate driver package that lacks anydisclosed grounded ring shield. The transmitter die is mounted on afirst die pad, the first receiver die is mounted on a second die pad,and the second receiver die is mounted on a third die pad. The signalbond pads and the die—to—die connections are the same as shown in FIG. 1.

FIG. 3B shows a disclosed dual channel gate driver package that includesa disclosed grounded ring shield for each of the respective dieincluding the first receiver die, a ring shield for the second receiverdie, and first and second transmitter ring shields for the transmitterdie, that each encircle their respective signal bond pads. Therespective die pads are each shorted to the ground pin(s) of the dualchannel gate driver package.

FIG. 3C shows an example dual channel gate driver package that includesthe ring shields and receiver die downbonds shown in FIG. 3B, andfurther includes a disclosed grounded peninsula shaped feature being anextension of the die pad of the transmitter die.

FIG. 4A shows simulated mutual capacitance data for the dual channelgate driver package shown in FIG. 3B and for the dual channel gatedriver package shown in FIG. 3C. This data evidences a reduction inmutual capacitance of about 40% and 50% respectively between the signalbond wires.

FIG. 4B shows simulated data for the dual channel gate driver packageshown in FIG. 3C evidencing a wire sweep immunity improvement being a 2×reduction in total differential capacitive coupling being provided.

DETAILED DESCRIPTION

Example aspects are described with reference to the drawings, whereinlike reference numerals are used to designate similar or equivalentelements. Illustrated ordering of acts or events should not beconsidered as limiting, as some acts or events may occur in differentorder and/or concurrently with other acts or events. Furthermore, someillustrated acts or events may not be required to implement amethodology in accordance with this Disclosure.

Also, the terms “connected to” or “connected with” (and the like) asused herein without further qualification are intended to describeeither an indirect or direct electrical connection. Thus, if a firstdevice “connects” to a second device, that connection can be through adirect electrical connection where there are only parasitics in thepathway, or through an indirect electrical connection via interveningitems including other devices and connections. For indirect connecting,the intervening item generally does not modify the information of asignal but may adjust its current level, voltage level, and/or powerlevel.

FIG. 1 depicts a block diagram representation of a known dual—channelgate driver package 100 showing signal bond wires 106 from firsttransmitter signal bond pads 121 a on the transceiver die 120 to signalbond pads 131 on the first receiver die 130, and other signal bond wires107 from second transmitter signal bond pads 121 b also on thetransceiver die 120 to signal bond pads 141 on the second receiver die140. Although not shown, as noted above in the background there is anisolation device generally comprising an isolation capacitor orisolation inductor connected in series on or between the transceiver die120 and the respective receiver die 130, 140. The respective die 130,140 are all on separate die pads (not shown).

The respective receiver die 130, 140 are each shown driving the gate ofa power NMOS transistor 151, 152 of a power NMOS device 150 that is thepower transistor part of a power converter circuit, where the respectivepower NMOS transistors 151, 152 are connected in series. Due to crosscoupling associated with the mutual capacitance (with example values ofmutual capacitance shown) between the signal bond wires 106 and signalbond wires 107 associated with the respective channels, some of thesignal for the first channel shown as channel A outputted by the packagepin OUTA when channel A is active, also is present on the second channeldriven by the second receiver die shown as channel B on the package pinOUTB shown being a square wave as OUTA′, when the output of channel Bshould instead be inactive (and thus have no signal on this pin due tono signal coming from the transmitter die).

FIG. 2 depicts a disclosed grounded shield metal feature shown in asimplified form as a trace 210 (the trace/guard metal feature is labeledas being grounded but is not shown grounded which it will be) that islocated between two adjacent metal features shown as S1 and S2 that caneach represent bond wires. The trace 210 being grounded and positionedbetween S1 and S2 reduces the mutual capacitance between the adjacentmetal features S1 and S2.

FIG. 3A shows a known dual channel gate driver package 300 that lacksany disclosed grounded ring shield. The transmitter die 120 is mountedon a first die pad 122, the first receiver die 130 is mounted on asecond die pad 132, and the second receiver die 140 is mounted on athird die pad 142. The signal bond pads and the die—to—die connectionsare the same as shown in FIG. 1 .

FIG. 3B shows a disclosed dual channel gate driver package 350 thatincludes a disclosed grounded ring shield for each of the respective die120, 130, 140 including the first receiver die 130 shown as 133, thering shield for the second receiver die 140 shown as 143, and first andsecond transmitter ring shields shown as 123 a and 123 b for thetransmitter die 120, that each encircle their respective signal bondpads. Although the ring shields all encircle their associated signalbond pads, they do not in any way physically touch them to provideelectrical isolation. Disclosed gate driver packages can have more thantwo channels.

There are signal bond wires 106 from the first transmitter signal bondpad 121 a on the transmitter die 120 to signal bond pads 131 on thefirst receiver die 130, and signal bond wires 107 from the secondtransmitter signal bond pads 121 b on the transmitter die 120 to signalbond pad 141 on the second receiver die 140. There is also a downbond136 between the ring shield 133 and the die pad 132 on the firstreceiver die 130, and a downbond 146 between the ring shield 143 and thedie pad 142 on the second receiver die 140. There is also a bond wire108 between a bond pad 129 on the transmitter die 120 that iselectrically connected to the ring shields 123 a and 123 b by anintegral metal connection depicted by a line, where the bond pad 129 isshown connected by the bond wire 128 to a GND leadframe pin shown as 351for grounding the ring shields 123 a and 123 b. Bond pad 129 may bereferred to as being a grounding bond pad. The ring shield 123 b,although not shown, can be connected to a separate grounding bond padthat includes a separate bond wire to a GND leadframe pin 351 or aanother GND pin.

The leadframe is configured so that the respective die pads 122, 132,142 are each shorted by a direct integral connection to a separateground pin, shown as GND, for the dual channel gate driver package 350,although it may be possible for a single GND pin to be used. Thecapacitive coupling between the respective channels caused by theadjacent signal bond wires 106 and 107 associated with these channels isreduced because the ring shields being grounded absorb some of theE-field coupling that would otherwise be present. A minimum width ofeach of the ring shields 123 a, 123 b, 133, 143 can be at least 2 timesa dimension of the respective signal bond pads 121 a, 121 b, 131, 141. Amaximum width of these ring shields can cover the whole surface of therespective die 120, 130 and 140 (with clearance of the signal die pads).A minimum spacing between the signal bond wires 106 and 107 can be equalto a pitch between the first, the second, and the third die pads. Themaximum spacing between the signal bond wires 106, 107 can depend on thedie layout, the die size and the manufacturing process. The leadframefor disclosed aspects may be formed using a process comprising etchingor stamping.

FIG. 3C shows an example dual channel gate driver package 380 thatincludes the ring shields and downbonds shown in FIG. 3B, and furtherincludes a disclosed grounded peninsula shaped feature 122a being anextension of the first die pad 122 of the transmitter die 120. There arealso downbonds shown as 109 from bond pads 129 a (that may be referredto as being grounding bond pads) on the transmitter die 120 that arepart of the respective ring shields 123 a, 123 b generally by anintegral metal connection, with this electrical connection shownrepresented by a line from the bond pads 129 a and 129 b to therespective ring shields 123 a, 123 b.

The peninsula shaped feature 122a extends into the region between therespective die pads 132, 142 of the respective receiver die 130, 140 fora portion of the distance between the second and third die pads 132, 142of the respective receiver die 130, 140 and the first die pad 122 of thetransmitter die 120. The peninsula shaped feature 122a can extend allthe way to be even with the outer edge of the second and third die pads132, 142 for the respective receiver die 130, 140 provided the minimummetal to metal spacing between the transmitter die 120 and therespective receiver die 130, 140 provided high-voltage isolation ismaintained.

EXAMPLES

Disclosed aspects are further illustrated by the following specificExamples, which should not be construed as limiting the scope or contentof this Disclosure in any way.

FIG. 4A shows simulated data for mutual capacitance for the dual channelgate driver package 350 shown in FIG. 3B and for the dual channel gatedriver package 380 shown in FIG. 3C. A simplified depiction for the dualchannel gate driver package 380 is shown as 380′ now with identificationof the signal bond wires 107 as 1, and 2 and the signal bond 106 as 3and 4 which is used in the tables for all the packages 300, 350 and 380provided in FIG. 4A and 4B. This data evidences a reduction in mutualcapacitance of about 40% and 50% respectively between the signal bondwires 106, and 107.

In the wire sweep immunity test, wire sweep happens during IC packagingassembly processing when the mold compound is injected into the moldchase, where the flow of the mold compound causes the sweep of bondwires, sometimes resulting in shorts or in this case, additionalcoupling of the bond wires degrading device performance. This testensures that the sweep is within an acceptable range. FIG. 4B showssimulated data for the dual channel gate driver package 380 shown inFIG. 3C as compared to the dual channel gate driver package 300 shown inFIG. 3A evidencing a wire sweep immunity improvement being a 2×reduction in total differential capacitive coupling provided followingwire sweep testing.

Disclosed aspects can be integrated into a variety of assembly flows toform a variety of different semiconductor packages and related products.The semiconductor package can comprise single IC die or multiple IC die,such as configurations comprising a plurality of stacked IC die, orlaterally positioned IC die. A variety of package substrates may beused. The IC die may include various elements therein and/or layersthereon, including barrier layers, dielectric layers, device structures,active elements and passive elements including source regions, drainregions, bit lines, bases, emitters, collectors, conductive lines,conductive vias, etc. Moreover, the IC die can be formed from a varietyof processes including bipolar, insulated-gate bipolar transistor(IGBT), CMOS, BiCMOS and MEMS.

Those skilled in the art to which this Disclosure relates willappreciate that many variations of disclosed aspects are possible withinthe scope of the claimed invention, and further additions, deletions,substitutions and modifications may be made to the above-describedaspects without departing from the scope of this Disclosure.

1. A multi-channel gate driver package, comprising: a leadframeincluding a plurality of leads and a first die pad, a second die pad,and a third die pad; a transmitter die including first circuitryelectrically connected to transmitter bond pads including a firsttransmitter signal bond pad and a second transmitter signal bond padboth on the first die pad, a first receiver die including secondcircuitry electrically connected to second bond pads including a secondsignal bond pad on the second die pad, and a second receiver dieincluding third circuitry electrically connected to third bond padsincluding a third signal bond pad on the third die pad; a first bondwire between the first transmitter signal bond pad and the second signalbond pad, and a second bond wire between the second transmitter bond padand the third signal bond pad; a first and a second transmitter ringshield on the transmitter die positioned around the first and the secondtransmitter signal bond pads, respectively, a second ring shield on thefirst receiver die positioned around the second signal bond pad, and athird ring shield on the second receiver die positioned around the thirdsignal bond pad, and a downbond from the second ring shield to thesecond die pad, and from the third ring shield to the third die pad, aconnection electrically connecting the first and second transmitter ringshields to at least one ground pin selected from the plurality of leads,wherein the second die pad and the third die pad each include a directintegral connection to the ground pin.
 2. The multi-channel gate driverpackage of claim 1, wherein the first die pad includes the directintegral connection.
 3. The multi-channel gate driver package of claim1, further comprising a peninsula shaped region extending from the firstdie pad at least a portion of a distance to the second die pad and thethird die pad, wherein the transmitter bond pads further includes afirst grounding bond pad electrically connected to the first transmitterring shield and second grounding bond pad electrically connected to thesecond transmitter ring shield, and wherein there is at least onedownbond between the first grounding bond pad and the peninsula shapedregion, and at least one downbond between the second grounding bond padand the peninsula shaped region.
 4. The multi-channel gate driverpackage of claim 3, wherein the peninsula shaped region extends from thefirst die pad at least 50% of a distance to the second die pad and tothe third die pad.
 5. The multi-channel gate driver package of claim 1,wherein the first ring shield, the second ring shield, and the thirdring shield are all formed from a top metal layer also used for thetransmitter bond pads, the second bond pads, and the third bond pads,respectively.
 6. The multi-channel gate driver package of claim 1,wherein a minimum width of the first and second transmitter ring shield,the second ring shield, and the third ring shield are all at least 2times a dimension of the first transmitter signal bond pad, the secondtransmitter signal bond pad, the second signal bond pad, and the thirdsignal bond pad, respectively.
 7. The multi-channel gate driver packageof claim 1, wherein the first signal bond wire and the second signalbond wire both comprise a plurality of bond wires.
 8. The multi-channelgate driver package of claim 1, wherein a minimum spacing between thefirst bond wire and the second bond wire is equal to a pitch between thefirst, the second and the third die pads.
 9. A method of forming amulti-channel gate driver package, comprising: providing a transmitterdie including first circuitry electrically connected to transmitter bondpads including a first transmitter signal bond pad and a secondtransmitter signal bond pad on a first die pad, a first receiver dieincluding second circuitry electrically connected to a second bond padincluding a second signal bond pad on a second die pad, and a secondreceiver die including third circuitry electrically connected to thirdbond pads including a third signal bond pad on a third die pad; a firstbond wire between the first transmitter signal bond pad and the secondsignal bond pad, and a second bond wire between the second transmittersignal bond pad and the signal third bond pad; forming a top metal layerincluding a first transmitter ring shield and a second transmitter ringshield on the transmitter die; a second ring shield on the firstreceiver die, and a third ring shield on the second receiver diepositioned around the first, second, and the third signal bond pad,respectively; mounting on a leadframe including a plurality of leads thefirst die pad, the second die pad and the third die pad, the transmitterdie being mounted on the first die pad, the first receiver die beingmounted on the second die pad and the second receiver die being mountedon the third die pad; wirebonding to form a downbond from the secondring shield to the second die pad, and from the third ring shield to thethird die pad and forming a connection electrically connecting the firstand second transmitter ring shield to at least one ground pin selectedfrom the plurality of leads, wherein the second die pad and the thirddie pad, each include a direct integral connection to the ground pin.10. The method of claim 9, further comprising forming the leadframeusing a process comprising etching or stamping.
 11. The method of claim9, wherein the first die pad includes the direct integral connection.12. The method of claim 9, wherein the multi-channel gate driver packagefurther comprises a peninsula shaped region extending from the first diepad at least a portion of a distance to the second die pad and the thirddie pad, and wherein the transmitter bond pads further includes a firstgrounding bond pad electrically connected to the first transmitter ringshield and a second grounding bond pad electrically connected to thesecond transmitter ring shield, forming at least one downbond betweenthe first grounding bond pad and the peninsula shaped region providingan electrical connection between the first transmitter ring shield andthe peninsula shaped region and from the second grounding bond pad andthe peninsula shaped region providing an electrical connection betweenthe second transmitter ring shield and the peninsula shaped region. 13.The method of claim 12, wherein the peninsula shaped region extends fromthe first die pad at least 50% of a distance to the second die pad andto the third die pad.
 14. The method of claim 9, wherein the first ringshield, the second ring shield, and the third ring shield are all formedfrom a top metal layer also used for the transmitter bond pads, thesecond bond pads, and the third bond pads, respectively.
 15. The methodof claim 9, wherein a minimum width of the first and second transmitterring shield, the second ring shield, and the third ring shield are allat least 2 times a dimension of the first transmitter signal bond pad,the second transmitter signal bond pad, the second signal bond, and thethird signal bond pad, respectively.
 16. The method of claim 9, whereinthe first signal bond wire and the second signal bond wire both comprisea plurality of bond wires.
 17. The method of claim 9, wherein a minimumspacing between the first bond wire and the second bond wire is equal toa pitch between the first, the second and the third die pads.
 18. Amulti-channel gate driver package, comprising: a leadframe including aplurality of leads and a first die pad, a second die pad, and a thirddie pad; a transmitter die including first circuitry electricallyconnected to transmitter bond pads including a first transmitter signalbond pad and a second transmitter signal bond pad both on the first diepad, a first receiver die including second circuitry electricallyconnected to second bond pads including a on the second die pad, and asecond receiver die including third circuitry electrically connected tothird bond pads including at least one third signal bond pad on thethird die pad; a first bond wire between the first transmitter signalbond pads and the second signal bond pad, and a second bond wire betweenthe second transmitter signal bond pad and the third signal bond pad; afirst and a second transmitter ring shield on the transmitter diepositioned around the first transmitter signal bond pad and the secondtransmitter signal bond pad, respectively, a second ring shield on thefirst receiver die positioned around the second signal bond pad, and athird ring shield on the second receiver die positioned around the thirdsignal bond pad, and a downbond from the second ring shield to thesecond die pad, and from the third ring shield to the third die pad, anda connection connecting the first and second transmitter ring shield toat least one ground pin selected from the plurality of leads, whereinthe second die pad and the third die pad each include a direct integralconnection to the ground pin, and a peninsula shaped region extendingfrom the first die pad at least a portion of a distance to the seconddie pad and the third die pad, wherein the transmitter bond pads furtherincludes a first grounding bond pad electrically connected to the firsttransmitter ring shield and second grounding bond pad electricallyconnected to the second transmitter ring shield, and wherein there is atleast one downbond between the first grounding bond pad and thepeninsula shaped region, and at least one downbond between the secondgrounding bond pad and the peninsula shaped region, wherein the firstdie pad includes the direct integral connection.
 19. The multi-channelgate driver package of claim 18, wherein a minimum width of the firstand second transmitter ring shield, the second ring shield, and thethird ring shield are all at least 2 times a dimension of the firsttransmitter signal bond pad, the second transmitter signal bond pad, thesecond signal bond pad, and the third signal bond pad, respectively. 20.The multi-channel gate driver package of claim 18, wherein the firstring shield, the second ring shield, and the third ring shield are allformed from a top metal layer also used for the transmitter bond pads,the second bond pads, and the third bond pads, respectively.